Method for compactly placing material in a well

ABSTRACT

A method for compactly placing a material such as gravel in a well bore exteriorly of a casing at a substantial depth by vibrating the stationary casing through the use of one or more devices positioned in the casing that are actuated by manipulation, rotation or reciprocation, of a drill pipe extending to the surface of the well. The device includes a member which is spring biased and movable relative to the drill pipe with a latch element for repeatedly biasing and releasing the member to impact the casing during continued manipulation of the drill pipe.

United States Patent 1 6 1,209 Solum 1 May 9, 1972 54 METHOD FORCOMPACTLY PLACING 3,239,005 3/1966 Bodine ..166/286 MATERIAL IN A WELL3,335,801 8/1967 Wilsey ..166/286 x Primary ExuminerDavid H. BrownAttorney-Lyon & Lyon [57] ABSTRACT A method for compactly placing amaterial such as gravel in a well bore exteriorly of a casing at asubstantial depth by vibrating the stationary casing through the use ofone or more devices positioned in the casing that are actuated bymanipulation, rotation or reciprocation, of a drill pipe extending tothe surface of the well. The device includes a member which is springbiased and movable relative to the drill pipe with a latch element forrepeatedly biasing and releasing the member to impact the casing duringcontinued manipulation of the drill pipe.

4 Claims, 4 Drawing Figures METHOD FOR COMPACTLY PLACING MATERIAL IN AWELL This invention relates to both a new method for compactly placingthe material in the annulus of a well bore in which there is positioneda liner or casing and an apparatus for performing the method. Inparticular the method is appliable to conventional procedures such asgravel packing of oil wells to improve the compaction of the gravel orthe cementing of the casing in a well bore.

There are numerous operations and processes performed in the drillingand completion of oil or water wells which involve placing a fluid orgranular material in the annular space between the exterior of a wellpipe and the wall of the well bore and in most situations it is highlydesirable to achieve the maximum possible compaction or fill of materialin the annular space. One such process employed in both water and oilwells that exhibit certain undesirable conditions such as producing finesand with the production fluid is commonly known as gravel packing"which involves positioning a perforated or slotted liner in the wellbore and filling the annular space with accurately sized gravel topreclude the intrusion of the sands. Obviously any voids, cavities orloose placement of the gravel in the annulus will detract from theoverall beneficial effect desired. During the gravel packing process itis impossible to move the slotted liner once the filling of the annularspace is started and therefore it has heretofore been impossible tobeneficially affect the degree of gravel fill or compaction other thanby careful dispersion of the gravel in the carrying fluid or theapplication of extreme fluid pressure which is often undesirable.

In still other operations involving the filling of the annular spaceexterior of a casing with a particular material, such as in cementingthe casing, it is usually possible and is relatively common to rotate orreciprocate the casing to, in part, enhance the material fill. Howeverin some well conditions it is impossible to move the casing as forexample in highly deviated wells where the operator must be satisfied tomerely run the casing to the desired location and he cannot riskdamaging or sticking the casing by attempting rotation or reciprocation.

Accordingly it is a principal object of this invention to provide anovel method and apparatus for mechanically vibrating a liner or casingpositioned at a remote depth in a well by providing a mechanical devicewithin the liner or casing which is actuated by manipulation of a drillpipe extending to the surface of the well whereby the device impacts andvibrates the liner or casing.

Another object of this invention is to provide a novel method forcompacting a material externally of a casing fixedly positioned in awell bore by mechanically vibrating the casing through the manipulationof a drill pipe extending into the casing from the well surface.

A further object of this invention is to provide a novel device adaptedfor mounting on a drill pipe string and fitting within a slotted linerwith an element releasably engaging a liner slot and having a limitedspring-biased movement relative to the drill pipe whereby movement ofthe drill pipe causes repeated engagement and disengagement of thedevice with the slotted liner thereby causing vibration of the liner. Astill further object is to provide such a device responsive torotational movement of the drill pipe and'having fins for also causingsubstantial fluid turbulence due to the repeated engagement anddisengagement to further enhance the material compaction.

Still another object of this invention is to provide a novel method andapparatus for compacting material in the annulus surrounding animmovable well casing including providing a multiplicity of impactingdevices along the length of drill pipe substantially equal to the lengthof casing where compaction of the material is desired, manipulating thedrill pipe from the well surface to cause actuation of the impactingdevices to vibrate the casing and filling the annular space with thedesired material during continuance of the manipulation of the drillpipe and vibration of the casing.

Other and more detailed objects and advantages of this invention willappear from the following description and the accompanying drawingswherein:

FIG. 1 is a diagrammatic illustration of a typical slant-drilled well inwhich the method and apparatus of this invention may be used for gravelpacking.

FIG. 2 is a sectional elevation of one form of an impact device of thisinvention positioned in a slotted liner pipe.

FIG. 3 is a sectional elevation of a device shovm in FIG. 2 in aposition of disengagement with the slots of the liner pipe as will occurat the beginning of vibration force imposing movement of the devicerelative to the liner pipe.

FIG. 4 is a sectional plan view of the impacting device takensubstantially on the line 4-4 in FIG. 2.

The method of this invention will be described specifically with respectto gravel packing wells but it will be readily understood by thoseskilled in the art that the method may also be used for a variety ofother processes and operations involving the placing of materialexternally of a well pipe including the conventional cementation of acasing in a well bore. Further the method of this invention will bedescribed with respect to a specific form of vibration or impactingdevice although it will readily be appreciated that numerous other formsof devices would be usable in the method.

Referring now to FIG. I of the drawings, the derrick l0, ground level 11and the initial portion I2 of the well are shown diagrammatically whilethe lower portion of the figure illustrates the producing zone of thewell in a somewhat less diagrammatic and an enlarged scale. The lowerportion of the well is shown as slant-drilled which is a relativelycommon practice and further illustrates an advantage of this inventionas will appear more fully hereinafter. Further it is to be noted thatwhile FIG. 1 illustrates a rather small deviation from a verticallydrilled well, it is now becoming relatively common to slant-drill wellsat angles up to 70 deviation from vertical and with varying deviationswhereby the vertical profile of the well may form a somewhat S curve. Insuch wells the problems involved with placing a material andmanipulating the casing are compounded and the method and apparatus ofthis invention become even more useful.

In a typical oil well to be gravel packed a well casing 13 will becemented in the well bore to the depth of the producing zone 14 whichmay be left as open hole, as shown, or also contain a cemented casingappropriately perforated to admit the production fluid. Where theproduction zone 14 exhibits characteristics requiring or rendering ravelpacking advantageous, a perforated or slotted liner I5 is employedhaving slots or perforations of a size selected in conjunction withselection of the gravel to preclude the gravel from passing through theperforations or slots. One typical form of liner is shown in FIGS. 2, 3and 4 in which longitudinal slots 16 are cut in the liner incircumferentially spaced relationship. The appropriate length of linerI5 is run into the well bore with a releasing tool 17 connected to thetop of the liner and a so called cross-over tool 18 thereabove. Whenappropriately manipulated at the conclusion of the gravel packing thereleasing tool 17 serves to disconnect the liner 15 from the cross-overtool 18 and drill pipe 19 used to lower the liner into the well.Conventional well packers and liner hangers may also be used but do notform any part of this invention and therefore have been omitted forsimplicity. As is well known, the cross-over tool 18 includes resilientsealing elements 20 and appropriate upper and lower ports 21 and 22,respectively, whereby fluid pumped downwardly through drill pipe 19 willflow outwardly through the lower port 22 into the annular spaceexternally of the liner I5 and fluid returning internally of the liner15 will flow outwardly through upper port 21 into the annular spacebetween the casing I3 and drill pipe 19 to return to the well surface.In this manner the gravel dispersed in fluid may be pumped downwardlythrough drill pipe 19 and pass through cross-over tool 18 into theannular space externally of liner 15 to deposit the gravel in the space,allowing the fluid to enter the slots 16 and return to the well surfacein the annular space between casing 13 and drill pipe 19. As thus fardescribed, the gravel packing procedure and the tools are somewhatconventional.

In order to accomplish the method of this invention, a length of drillpipe 23 or other relatively strong pipe, such as a thick-walled washpipe, is connected to the liner releasing tool 17 and cross-over tool 18and extends downwardly through a substantial proportion of the slottedliner 15. The pipe 23 is connected through tools 17 and 18 in a mannerwhereby rotation of the drill pipe 19 from the surface of the well willcause rotation of pipe 23. The connection between releasing tool 17 andliner is such that through appropriate manipulation either the liner 15will be released or at least the pipe 23 will be rotatable relativethereto upon rotation of the drill pipe 19 during placement of thegravel.

Means are provided on the well pipe 23 for impacting and vibrating theliner 15 and, as shown in the drawings, these means may include aplurality of impacting devices, generally designated 25, positioned inspaced relation along the pipe 23. Any convenient spacing of devices 25along pipe 23 may be used as dictated by the particular circumstancesand for convenience it is contemplated that a device 25 will be providedas a coupling between each joint of pipe 23 thereby producing a spacingof approximately feet under the usual conditions of 30 foot joints ofpipe.

Referring more particularly to FIGS 2, 3 and 4, each impacting device 25includes a collar member 26 rotatably mounted on a section of tubing 27which is connected by threads 28 at both ends into the string of wellpipe 23. A collar or flange 29 is fixedly mounted on tubing 27 by setscrew 30 and/or weld 31. The flange 29 supports the collar 26 againstlongitudinal downward movement as shown in the figures. A second collaror flange 32 is fixedly mounted to tubing 27 above collar 26 by setscrew 33 and/or weld 34. A plurality of fins 35 are mounted on collar 26to extend longitudinally for engaging the interior of the liner 15partially to center the well pipe 23 within the liner 15. As shown inFIG. 4 it is preferred that three fins 35 be provided and spaced 90apart although more or fewer fins may be used. Each fin 35 is preferablyof a longitudinal length greater than the length of each slot 16 in theliner pipe 15 whereby the fin bridges the slot and further that the fins35 be of a thickness to also bridge each slot 16 in the circumferentialdirection.

A latching and releasing mechanism is provided on the collar 26 forrepeatedly connecting and disconnecting the collar from the liner pipe15 and, as shown in the drawings, this mechanism may include a slide bar36 mounted in collar 26 for sliding, radial movement. A compressionspring 37 is captured between the base of slide bar 36 and the collar 26to reiliently urge the slide bar 36 radially outwardly. The slide bar 36has a tapered nose portion 38 which is sufficiently pointed to projectinto and engage the interior of a slot 16 in the liner 15 as shown inFIG. 2. The upper and lower extremities of the nose portion 38 may berounded as shown to permit longitudinal entry into and exit from theslots 16 as the well pipe 23 is moved longitudinally relative to theliner pipe 15. A coil torsion spring 40 encircles tubing 27 betweencollar 26 and flange 32 and has one end 41 anchored to flange 32 such asby a bolt 42. The other end 43 of coil torsion spring 40 is connected tothe slide bar 36 such as by a bolt 44. Thus rotation of collar 32relative to collar 26 will cause stressing of the spring 40. Since it ispreferred in general oil field practice to rotate drill pipe in aright-hand direction to avoid unthreading, the spring 40 is coiled in acounter-clockwise direction proceeding from end 41 to end 43 when viewedfrom above. In this manner as pipe 23 is rotated in a clockwisedirection to in turn rotate collar 32 the spring 40 will be wound in adirection toward tightening on the tubing 27 since the collar 26 is heldagainst rotation by engagement of the slide bar 36 with a slot 16.However as the coil torsion spring 40 is tightened from the unstressedcondition shown in FIG. 2 toward the condition shown in FIG. 3, thespring is stressed to store energy and eventually the end 43 of thespring will pull inwardly on the slide bar 36 in opposition to theoutward force of spring 37. This will pull the nose 38 of the slide barfree from a slot 16 whereupon the collar 26 will be free to rotaterelative to the liner l5 and the energy stored in the torsion spring 40will cause rapid rotation in excess of the speed of rotation of the pipe23. During this rapid rotation of the nose portion 38 of slide bar 36will repeatedly engage slots 15 around the circumference of liner 15'and each such engagement will produce an impact on liner 15 with aresultant vibration being induced. Eventually the speed of rotation ofcollar 26 will decrease to the point where the nose portion 38 of slidebar 36 will again become engaged in a slot 16 to resist rotation ofcollar 26 relative to liner pipe 15. Continuing rotation of well pipe 23repeatedly causes this cycle of engagement of the slide bar 36, biasingof the torsion spring 40 and the release to produce vibration. The fins35 and also the slide bar 36 induce substantial fluid turbulence duringthe rapid rotation of collar 26 to further enhance the gravelcompaction.

Since the impacting devices are provided in space relation along theentire length of the liner 15 the liner is effectively vibrated for itsentire length but without requiring any rotational or reciprocalmovement of the liner. Each impacting device 25 operates independentlyof the others and therefore the torsional forces induced in the wellpipe 23 are not necessarily cummulative to an undesirable magnitude.Each of the impacting devices 25 may be specifically located to bedirectly opposite and in alignment with a circumferential series ofslots 16 or merely a random placement of more than adequate number ofimpacting devices 25 will naturally be positioned to engage slots 16. Asan alternative, and in unslotted casing and liners, the interior of theliner casing may be provided with longitudinal grooves or fixedlymounted bars to engage the slide bar 36 for producing the vibrationalforces. In addition to the beneficial vibration produced by rotation ofthe drill pipe 19 during placement of the gravel, such rotation alsoserves to maintain the gravel dispersed in fluid suspension while beingpumped downwardly through the drill pipe and prevents any gravel fromaccumulating at the couplings between joints of drill pipe which wouldotherwise occur with well bores inclined at substantial angles from thevertical. It is to be noted that the connections between joints of linerpipe 15 should be made extremely tight or even pennanent by weldingsince the vibrational and torsional shock forces induced by theimpacting devices may otherwise tend to unthread the joints of linerpipe, particularly if the upper end of the liner pipe is secured againstrotation such as by a liner hanger.

Having fully described my invention in connection with a specificembodiment of the impacting device 25 which is actuated by rotation ofthe drill pipe and further in specific connection with a gravel packingprocess for clarity of understanding and description of the invention,it is to be understood and will readily appear to those skilled in theart that my invention may be performed by and include impacting deviceshaving a variety of constructions and is applicable to numerousprocesses in the completion of wells and therefore is not to be limitedto the herein described embodiment and method.

I claim:

1. In a method for compacting a material in the annular space of a wellbore exteriorly of a casing remotely positioned in the well, comprisingthe steps of extending a drill pipe from the well surface to a positionwithin the casing, providing at least one mechanical impacting device onsaid drill pipe at a point to be removably positioned within the casing,manipulating the drill pipe from the well surface for causing actuatingmovement of said mechanical device for physically impacting against andvibrating the casing while retaining the casing in the same position,and pumping the material through the drill pipe to the casing and intothe annular space while continuing said manipulation of the drill pipe.

2. In a method for compacting a material in the annular space of a wellbore exteriorly of a casing remotely positioned in the well, comprisingthe steps of providing a drill pipe of a length for extending from thewell surface to a position within the casing, providing at least onerotation-actuated impacting device and said drill pipe at a pointtherealong to be positioned in the casing, lowering the drill pipe intothe well and casing, rotating the drill pipe from the well surface whilepumping the material into the annular space for causing actuation ofsaid impacting device for physically impacting against and vibrating thecasing.

3. In a method for gravel packing the producing zone of a well,comprising the steps of positioning a slotted liner in the producingzone with a drill pipe extending from the well surface to a positionwithin the liner, providing a fluid cross-over tool on the drill pipe atthe top of the liner, providing at least one rotationally-actuatedimpacting device on said drill pipe at a point within the liner, pumpingfluid and gravel down the drill pipe and through the cross-over toolinto the annulus externally of the liner to deposit the gravel in theannulus and returning the fluid through the cross-over tool to the wellsur' face externally of the drill pipe, the drill pipe from the wellsurface for causing actuation of said impacting device for physicallyvibrating the liner and compacting the gravel in the annulus duringplacement of the gravel in the annulus.

4. The method of claim 3 including providing the impacting device withfins and causing fluid turbulence during gravel placement by suchrotation.

1. In a method for compacting a material in the annular space of a wellbore exteriorly of a casing remotely positioned in the well, comprisingthe steps of extending a drill pipe from the well surface to a positionwithin the casing, providing at least one mechanical impacting device onsaid drill pipe at a point to be removably positioned within the casing,manipulating the drill pipe from the well surface for causing actuatingmovement of said mechanical device for physically impacting against andvibrating the casing while retaining the casing in the same position,and pumping the material through the drill pipe to the casing and intothe annular space while continuing said manipulation of the drill pipe.2. In a method for compacting a material in the annular space of a wellbore exteriorly of a casing remotely positioned in the well, comprisingthe steps of providing a drill pipe of a length for extending from thewell surface to a position within the casing, providing at least onerotation-actuated impacting device and said drill pipe at a pointtherealong to be positioned in the casing, lowering the drill pipe intothe well and casing, rotating the drill pipe from the well surface whilepumping the material into the annular space for causing actuation ofsaid impacting device for physically impacting against and vibrating thecasing.
 3. In a method for gravel packing the producing zone of a well,comprising the steps of positioning a slotted liner in the producingzone with a drill pipe extending from the well surface to a positionwithin the liner, providing a fluid cross-over tool on the drill pipe atthe top of the liner, providing at least one rotationally-actuatedimpacting device on said drill pipe at a point within the liner, pumpingfluid and gravel down the drill pipe and through the cross-over toolinto the annulus externally of the liner to deposit the gravel in theannulus and returning the fluid through the cross-over tool to the wellsurface externally of the drill pipe, the drill pipe from the wellsurface for causing actuation of said impacting device for physicallyvibrating the liner and compacting the gravel in the annulus duringplacement of the gravel in the annulus.
 4. The method of claim 3including providing the impacting device with fins and causing fluidturbulence during gravel placement by such rotation.